JPWO2013051102A1 - Inductor wire and inductor - Google Patents

Abstract

In providing a magnetic layer on a surface layer of a conductor, an inductor wire capable of increasing a Q value in consideration of a resistance value and an inductor using the wire are provided. An inductor wire used for a coil of an inductor, comprising an electric conductor and a magnetic layer provided on a surface layer of the electric conductor, wherein the thickness of the magnetic layer is larger than 0 and 3.0 μm. It is as follows. Using this wire, an inductor having a high Q value is obtained.

Description

  The present invention relates to an inductor wire used for a winding of an inductor and an inductor using the wire.

  As a wire for winding for manufacturing an inductor, a wire having an insulating layer outside a conductor such as copper is generally used.

  Also known is a wire material in which a magnetic material is plated on the surface of the conductor. It is disclosed that an inductor using this wire has an effect of an inductance UP of about 10% in a frequency band of 1 MHz (for example, see Japanese Patent Application Laid-Open No. Sho 62-219044).

  The performance of an inductor is generally expressed by a high Q value (Q value = 2π × frequency × inductance Ls / winding resistance Rs). Although the above-mentioned document describes that the inductance L increases, the relationship with respect to the resistance value R is unknown. Moreover, in the said literature, the relationship with the material and thickness of a magnetic body layer is not described. On the other hand, in the resonant circuit disclosed in this document, it is described about lowering the Q value, but it is not described about increasing the Q value (lowering the resistance value).

  An object of the present invention has been made in view of the above-described circumstances, and provides an inductor wire and an inductor capable of increasing a Q value in consideration of a resistance value in providing a magnetic layer on a surface layer of a conductor. It is to provide.

  In order to achieve the above object, according to the present invention, there is provided an inductor wire used for an inductor coil, comprising a conductor and a magnetic layer provided on a surface layer of the conductor, wherein the magnetic The thickness of the body layer is greater than 0 and 3.0 μm or less.

  Preferably, when the operating frequency band is 0.01 to 1000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 100 to 500, and the thickness of the magnetic layer is less than 0. It is 3.0 μm or less.

  Also preferably, when the operating frequency band is 0.01 to 5000 kHz or less, the value of the initial permeability of the magnetic layer expressed by relative permeability is 100 to 500, and the thickness of the magnetic layer is 0. It is larger than 2.0 μm.

  Preferably, when the frequency band used is 0.01 to 1000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 500 to 2000, and the thickness of the magnetic layer is 0. It is larger than 2.5 μm.

  Preferably, when the frequency band used is 0.01 to 1000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 500 to 2000, and the thickness of the magnetic layer is 0. It is larger than 2.0 μm.

  Preferably, when the used frequency band is 0.01 to 5000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 500 to 2000, and the thickness of the magnetic layer is 0.5 to 1.5 μm.

  Further, the magnetic layer may be an alloy of two or more elements containing 10% or more by weight of Fe.

  The magnetic layer may be an Fe-50Ni alloy.

  Further, the magnetic layer may be an Fe-80Ni alloy.

  Furthermore, the magnetic layer may be substantially made of Fe.

  Further, the thickness of the magnetic layer substantially made of Fe may be greater than 0 μm and not greater than 3.0 μm, and more preferably not less than 1.5 μm and not greater than 3.0 μm.

  In these cases, the magnetic layer may be provided between the conductor and the insulating layer.

  On the other hand, an inductor can be manufactured using the above-described inductor wire.

  The inductor wire according to the present invention is an inductor wire used for a coil of an inductor, and includes a conductor and a magnetic layer provided on a surface layer of the conductor. The thickness is greater than 0 and not greater than 3.0 μm. That is, since the magnetic layer having the predetermined thickness is provided on the surface layer of the conductor, the inductance can be improved, the resistance value can be lowered, and the Q value can be increased as compared with the wire without the magnetic layer. .

FIG. 1 is a cross-sectional view schematically showing the configuration of the electromagnet wire according to the first embodiment of the present invention. FIG. 2A and FIG. 2B are cross-sectional views of the electromagnet wire when a flat wire is used. FIG. 3 is a cross-sectional view of an air-core coil using an inductor wire. FIG. 4 is a graph showing the relationship between the frequency and inductance of the air-core coil. FIG. 5 is a graph showing the relationship between the frequency of the air-core coil and the inductance change rate. FIG. 6 is a graph showing the relationship between the plating thickness and the inductance change rate when an Fe alloy is used for the magnetic layer. FIG. 7 is a graph showing the relationship between the plating thickness and the rate of resistance change when an Fe alloy is used for the magnetic layer. FIG. 8 is a graph showing the relationship between the plating thickness and the Q value change rate when an Fe alloy is used for the magnetic layer. FIG. 9 is a graph showing the relationship between the plating thickness and the inductance change rate when an Fe-80Ni alloy is used for the magnetic layer. FIG. 10 is a graph showing the relationship between the plating thickness and the rate of resistance change when an Fe-80Ni alloy is used for the magnetic layer. FIG. 11 is a graph showing the relationship between the plating thickness and the Q value change rate when an Fe-80Ni alloy is used for the magnetic layer. FIG. 12 is a graph showing the relationship between the plating thickness and the inductance change rate when an Fe-50Ni alloy is used for the magnetic layer. FIG. 13 is a graph showing the relationship between the plating thickness and the rate of change in resistance when an Fe-50Ni alloy is used for the magnetic layer. FIG. 14 is a graph showing the relationship between the plating thickness and the Q value change rate when an Fe-50Ni alloy is used for the magnetic layer. FIG. 15 is a sectional view showing a state in which two air-core coils are used. FIG. 16: is sectional drawing which shows roughly the structure of the wire material for electromagnets based on the 2nd Embodiment of this invention. FIG. 17 is a sectional view of a solenoid for testing the attractive force of the electromagnet. 18A is a graph showing the relationship between the current and the attractive force in the attractive force test using the solenoid of FIG. 8, and FIG. 18B is a graph showing the change in the thickness of the magnetic layer and the attractive force. It is a graph which shows the relationship with a rate.

  Hereinafter, an inductor wire 1 according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a configuration of an inductor wire 1 according to a first embodiment of the present invention.

  The inductor wire 1 includes a conductor 2 that is a core of the wire, a magnetic layer 3 that covers the outside of the conductor 2, and an insulating layer 4 that covers the outer periphery of the magnetic layer 3.

  The conductor 2 has a circular cross-sectional shape, and copper having conductivity is used as a material.

  The magnetic layer 3 has conductivity and is formed to a thickness on the order of several μm, for example, a thickness greater than 0 and not greater than 3.0 μm. The magnetic layer 3 is formed by plating or the like so as to uniformly cover the entire outer periphery of the conductor 2. The material of the magnetic layer 3 is formed of an alloy of two elements or more containing Fe of 10% or more by weight. Moreover, it is preferably formed of an Fe-50Ni alloy or an Fe-80Ni alloy.

  The insulating layer 4 is an enamel insulating layer, for example, and has a thickness of about 35 μm.

  Further, the inductor wire can be formed of a flat wire as shown in FIG.

  In the inductor wire 11 shown in FIG. 2A, the conductor 12 that is the core of the wire has a rectangular cross-sectional shape, and the magnetic layer 13 is formed so as to cover the entire outside of the four sides. . Further, an insulating layer 14 is formed outside the magnetic layer 13 so as to cover the entire outside of the magnetic layer 13. Such a flat wire is excellent in that a gap is not generated between adjacent wires when the wire is wound around the core.

  In addition, an inductor wire 21 shown in FIG. 2B is obtained by forming a magnetic layer 23 only on the lower side of the lower side of the conductor 22 having a rectangular cross section. And the insulating layer 24 is formed so that these outer sides may be covered.

  Next, an experiment of an inductor using the inductor wire 1 according to the present embodiment will be described with reference to FIGS. In this example, the inductance change of the inductor when the material and film thickness of the magnetic layer of the inductor wire 1 are changed is verified by experiment.

  Conventionally, as such an inductance wire, one having only an insulating layer outside the conductor has been used. Further, it is known that the inductance Ls increases in the high frequency band by plating the magnetic layer, but the relationship with the resistance value Rs of the wire is not known. On the other hand, in this experiment, as a result of measuring the inductance Ls and the resistance value Rs of the wire from the viewpoint of the material and thickness of the magnetic layer, it was found that there is an optimum value for these relationships.

In this experiment, the following three types of wires are tested as inductor wires.
(A) Inductor wire 1A (wire diameter φ0.5)
Conductor: mainly copper
Magnetic layer: Fe-based alloy
Insulating layer enamel (35μm) outside the magnetic layer
(B) Inductor wire 1B (wire diameter φ0.5)
Conductor: mainly copper
Magnetic layer: Fe-50Ni with heat treatment
Insulating layer enamel (35μm) outside the magnetic layer
(C) Inductor wire 1C (wire diameter φ0.5)
Conductor: mainly copper
Magnetic layer: Fe-80Ni No heat treatment
Insulating layer enamel (35μm) outside the magnetic layer

  In the following description, the subscripts A, B, and C attached to the reference numerals correspond to the inductor wires (A), (B), and (C), respectively.

  The initial permeability of each of the inductor wires 1A, 1B, and 1C is 100, 2000, and 500 as relative permeability.

  The saturation magnetic flux densities (T) of the inductor wires 1A, 1B, and 1C are 2.0 (T), 1.5 (T), and 0.75 (T), respectively.

  As shown in FIG. 3, the air-core coil 30 </ b> A used in this experiment is formed by winding an inductor wire 1 </ b> A in a cylindrical shape and nothing is put in the cylinder. The air-core coil 30A has a diameter of 6 mm and a winding number of 17 turns.

  Similarly, the air-core coils 30B and 30C also have the same basic configuration except that the wire material (material of the magnetic layer) is different.

  With such a configuration, an experiment was first conducted on the relationship between the frequency of the band used and the inductance when the plating thickness was 3 μm.

  FIG. 4 is a graph showing the relationship between the frequency of the air-core coil and the inductance, and FIG. 5 is a graph showing the relationship between the frequency of the air-core coil and the inductance change rate. In these drawings, reference numeral 40A denotes a measured value with the air core coil 30A using the inductor wire 1A (plating thickness 3 μm), reference numeral 40B denotes a measured value with the air core coil 30B, and reference numeral 40C denotes an empty wire. The measured value in the core coil 30C is shown. Reference numeral 41 indicates a measurement value with an air-core coil formed of a wire without a magnetic layer (note that the measurement value of reference numeral 41 in FIG. 5 is omitted because the rate of change is 0% at any frequency). To do).

  From the experimental results shown in FIGS. 4 and 5, the following can be determined.

  (A) The air-core coils 30A, 30B, 30C (reference numerals 40A, 40B, 40C) using the inductor wires 1A, 1B, 1C are shown in FIG. 4 in the entire frequency band of 0.01 kHz to 10000 kHz. The inductance is higher than that of the wire (reference numeral 41) not provided with the magnetic layer. Accordingly, it is possible to determine that the inductance of the inductor wires 1A, 1B, and 1C is increased by providing the magnetic layer 3 made of an alloy of two or more elements containing Fe in a weight ratio of 10% or more on the surface layer of the conductor 2.

  In particular, the wire 1B provided with an Fe-50Ni alloy (air-core coil 40B, indicated by reference numeral 40B) has the highest value in the above-described all frequency bands (for example, at a frequency of 1000 kHz, the inductance is approximately twice that of reference numeral 41). It was found that

  Also, in the wire 1C provided with the Fe-80Ni alloy (air core coil 40C, indicated by reference numeral 40C), for example, at a frequency of 1000 kHz, an inductance approximately 1.7 times that of the reference numeral 41 is obtained.

  (B) Air core coils 30A, 30B, and 30C (reference numerals 40A, 40B, and 40C) using inductor wires 1A, 1B, and 1C are shown in FIG. 5 in the entire frequency band of 0.01 kHz to 10,000 kHz. Inductance change rate (referring to change rate with respect to an air-core coil using a wire without a magnetic layer) is improved.

  In particular, it has been found that the air core coils 30A, 30B, and 30C all have a higher inductance change rate in a frequency band of 1000 kHz or more than in a band of 1000 kHz or less. From this, it can be determined that high inductance can be obtained by providing a magnetic layer in a high frequency band.

Next, in the air-core coils 30A, 30B, and 30C described above, the inductance change and resistance value change when the film thickness (plating thickness) of the magnetic layer 3 is changed to 1.0 μm, 3.0 μm, and 5.0 μm. It was measured. At this time, since changes in inductance and resistance values differ depending on the frequency band, the frequencies were measured at values of 0.01 kHz, 0.1 kHz, 1 kHz, 2 kHz, 10 kHz, 20 kHz, 100 kHz, 1000 kHz, and 5000 kHz. The current value is 5 A / mm ² .

  And each Q value was computed from these measured values.

  6 to 8 show the relationship between the inductance, the resistance value, and the Q value with respect to the plating thickness in the air-core coil 30A, respectively. 6 to 8 (the same applies to FIGS. 9 to 14), data is measured for each frequency described above, and a line graph is created for each frequency (the frequency is shown below the graph). Show the distinction).

  From the graph of FIG. 6, it can be seen that the inductance Ls increases when the plating thickness is increased from 1.0 μm to 3.0 μm in all frequency bands.

  However, with respect to the resistance value R, as shown in FIG. 7, when the frequency band is 5000 kHz, the resistance value R decreases as the plating thickness increases from 1.0 μm to 2.0 μm. It was found that the resistance value R increases as the value increases from 0 μm to 3.0 μm. As shown in FIG. 8, the Q value increases as the plating thickness increases from 1.0 μm to 2.0 μm, but the Q value increases as the plating thickness increases from 2.0 μm to 3.0 μm. It was found that the value decreased. That is, in the portion where the Q value decreases, the increase in the resistance value R is larger than the increase in the inductance Ls, and thus the Q value decreases.

  From this, in order to increase the Q value of the air-core coil 30A, first, in the frequency band in which the air-core coil 30A is used, the resistance value Rs is set to a plating thickness that decreases by a predetermined amount compared to the case where plating is not performed. Good. Furthermore, it is more preferable that the plating thickness is such that the resistance value Rs is around the minimum value (or the minimum value).

  In addition, in the case of the air-core coil 30A used in the frequency band of 5000 kHz or higher, it is preferable that the plating thickness is about 2.0 μm (greater than 1 μm and smaller than 3 μm). I understand.

  9 to 11 show the relationship between the inductance, the resistance value, and the Q value with respect to the plating thickness in the air-core coil 30C, respectively.

  From the graph of FIG. 9, it can be seen that the inductance Ls increases when the plating thickness is increased from 1.0 μm to 3.0 μm in all frequency bands.

  However, with respect to the resistance value R, as shown in FIG. 10, when the frequency band is 1000 kHz, the resistance value R decreases as the plating thickness increases from 1.0 μm to 2.0 μm. It was found that the resistance value R increases as the value increases from 0 μm to 3.0 μm. As shown in FIG. 11, the Q value increases as the plating thickness increases from 1.0 μm to 2.0 μm, but the Q value increases as the plating thickness increases from 2.0 μm to 3.0 μm. It was found that the value decreased. That is, in the portion where the Q value decreases, the increase in the resistance value R is larger than the increase in the inductance Ls, and thus the Q value decreases.

  Similarly, if the same view is taken when the frequency band is 5000 kHz, as shown in FIG. 11, the Q value increases as the plating thickness increases from 0 μm (not including 0 μm) to 1.0 μm as shown in FIG. However, it was found that the Q value decreased as the plating thickness increased from 1.0 μm to 2.0 μm.

  From this, it can be seen that when the Q value of the air-core coil 30C is increased, it is first necessary to distinguish between the frequency bands. That is, in the case of the air-core coil 30C used in the frequency band of 1000 kHz (greater than 100 kHz and smaller than 5000 kHz), the plating thickness should be about 2.0 μm (greater than 1 μm and smaller than 3 μm). . In addition, in the case of the air-core coil 30C used in a band of 5000 kHz or higher, it can be seen that the plating thickness should be 1 μm (greater than 0 μm and smaller than 2 μm).

  Furthermore, the measurement results of 1000 kHz and 5000 kHz described above show that the Q value can be maximized (optimized) by reducing the thickness of the magnetic layer 3 as the operating frequency band increases. Moreover, although the maximum value of Q does not appear in the band of 1000 kHz or less in the measurement result this time, it is estimated that the above-described relationship between the size of the frequency band and the thickness of the magnetic layer 3 is established.

  12 to 14 show the relationship between the inductance, the resistance value, and the Q value with respect to the plating thickness in the air-core coil 30B, respectively.

  From the graph of FIG. 12, it can be seen that the inductance Ls increases when the plating thickness is increased from 1.0 μm to 3.0 μm in all frequency bands.

  However, with respect to the resistance value R, as shown in FIG. 13, when the frequency band is 1000 kHz (data plotted with a circle), the resistance value R increases as the plating thickness increases from 1.0 μm to 2.0 μm. However, the resistance value R increases as the plating thickness increases from 2.0 μm to 3.0 μm. Further, as shown in FIG. 14, the Q value increases as the plating thickness increases from 1.0 μm to 2.0 μm, but the Q value increases as the plating thickness increases from 2.0 μm to 3.0 μm. It was found that the value decreased. That is, in the portion where the Q value decreases, the increase in the resistance value R is larger than the increase in the inductance Ls, and thus the Q value decreases.

  Similarly, if the same view is taken when the frequency band is 5000 kHz, as shown in FIG. 14, the Q value increases as the plating thickness increases from 0 μm (not including 0 μm) to 1.0 μm. However, it was found that the Q value decreased as the plating thickness increased from 1.0 μm to 2.0 μm.

  From this, it can be seen that when the Q value of the air-core coil 30B is increased, it is first necessary to distinguish between the frequency bands. That is, in the case of the air-core coil 30B used in the frequency band of 1000 kHz (greater than 100 kHz and smaller than 5000 kHz), the plating thickness should be about 2.0 μm (greater than 1 μm and smaller than 3 μm). . In addition, in the case of the air-core coil 30B used in a band of 5000 kHz or higher, it can be seen that the plating thickness should be 1 μm (greater than 0 μm and smaller than 2 μm).

  Furthermore, from the measurement results of 1000 kHz and 5000 kHz described above, it can be determined that the Q value can be maximized (optimized) by reducing the thickness of the magnetic layer 3 as the operating frequency band increases. . Moreover, although the maximum value of Q does not appear in the band of 1000 kHz or less in the measurement result this time, it is estimated that the above-described relationship between the size of the frequency band and the thickness of the magnetic layer 3 is established.

  Further, focusing attention on the relative magnetic permeability, from the results of FIGS. 8 and 11, when the relative magnetic permeability is 100 to 500, the plating thickness is larger than 0 and not larger than 3.0 μm, preferably not smaller than 0.5 μm. It can be seen that a good Q value can be obtained when the frequency band is 0.01 to 1000 kHz or less when it is 0 μm or less. Moreover, in the relative permeability in the same range, when the plating thickness is larger than 0 and 2.0 μm or less, preferably 0.5 μm or more and 2.0 μm or less, the frequency band is 0.01 to 5000 kHz and a good Q value is obtained. It turns out that it is obtained.

  When the relative permeability is 500 to 2000, when the plating thickness is greater than 0 and 2.5 μm or less, preferably 0.5 μm or more and 2.0 μm or less, the frequency band is 0.01 to 1000 kHz or less, and good Q It can be seen that values are obtained (FIGS. 11 and 14). Moreover, in the relative permeability in the same range, when the plating thickness is larger than 0 and 2.0 μm or less, preferably 0.5 μm or more and 2.0 μm or less, a good Q value is obtained when the frequency band is 0.01 to 1000 kHz or less. It turns out that it is obtained. Furthermore, it can be seen that when the plating thickness is 0.5 to 1.5 μm within the same range of relative permeability, a good Q value can be obtained at a frequency band of 0.01 to 5000 kHz or less.

  According to the inductor wire according to the embodiment of the present invention, it is the inductor wire 1 (11, 21) used for the inductor coils 30A, 30B, 30C, and the surface layer of the conductor 2 (12, 22). Since the magnetic layer 3 (13, 23) having a thickness greater than 0 and 3.0 μm or less is provided on the coil 30A, the coils 30A, 30B, The inductance Ls of 30C can be improved, the resistance value R can be decreased, and the Q value can be increased.

  Further, since the magnetic layer 3 (13, 23) is an alloy of two or more elements including Fe in a weight ratio of 10% or more, particularly an Fe-50Ni alloy or an Fe-80Ni alloy, the magnetic layer 3 (13, 23) 23) can be easily formed by plating or the like.

  On the other hand, since the thickness of the magnetic layer 3 (13, 23) of the Fe-50Ni alloy or the Fe-80Ni alloy is reduced as the operating frequency band increases, the inductance Ls increases and the resistance R increases or decreases. A high Q value in consideration of That is, an optimum Q value can be realized.

  Further, the thickness of the magnetic material layer of the alloy of two or more elements containing Fe of 10% or more by weight is set to be larger than 1 μm and smaller than 3 μm when the operating frequency band is 5000 kHz or larger. A high Q value in consideration of the increase and the increase or decrease of the resistance R can be realized.

  Further, the thickness of the magnetic layer 3 (13, 23) of the Fe-50Ni alloy or the Fe-80Ni alloy is set to be larger than 1 μm and smaller than 3 μm when the operating frequency band is larger than 100 kHz and smaller than 5000 kHz. Therefore, it is possible to realize a high Q value considering the increase of the inductance Ls and the increase or decrease of the resistance R.

  Furthermore, since the thickness of the magnetic layer 3 (13, 23) of the Fe-50Ni alloy or the Fe-80Ni alloy is set to be larger than 0 μm and smaller than 2 μm when the operating frequency band is 5000 kHz or larger, A high Q value in consideration of an increase in inductance Ls and an increase or decrease in resistance R can be realized.

  Moreover, when FIGS. 6-14 is seen from the value of a relative magnetic permeability, when the relative magnetic permeability is in the range of about 100 to 2000, by setting the plating thickness to 0.5 to 3.0 μm, about 100 kHz to 5000 kHz, especially It can be seen that an inductor having a good Q value can be obtained in a frequency band of about 100 kHz to 1000 kHz.

  And within the range of the relative magnetic permeability, by lowering this value (about 100 to 500), the rate of increase in Q value is low, but a relatively wide plating thickness of about 0.5 to 2.5 μm. In the range, an inductor wire having a high Q value at a frequency of up to about 5000 kHz can be obtained.

  Further, when this value is increased (about 500 to 2000), a very high Q value can be obtained at a frequency up to about 5000 kHz in a plating thickness range of 0.5 to 1.5 μm. If the frequency band is about 1000 kHz, a higher Q value can be obtained with a plating thickness of 0.5 to 3.0 μm.

  In these cases, the magnetic layer 3 (13) is provided between the conductor 2 (12) and the insulating layer 4 (14), so that the conductor 2 (12) made of copper is used as the material. The magnetic layer 3 (13) can be easily formed by plating.

  In addition, by manufacturing an inductor using the above-described inductor wires 1, 11, and 21, it is possible to obtain an inductor that realizes a high Q value in consideration of an increase in inductance Ls and an increase or decrease in resistance R. .

  As described above, the inductor wire 1 (11, 21) according to the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various types of wires are based on the technical idea of the present invention. Variations and changes are possible.

  For example, in the experimental example of the air-core coils 30A, 30B, and 30C in the present embodiment, data is measured using one air-core coil. As an application example thereof, as shown in FIG. As described above, the power transmitted using the two air-core coils 50 (the receiving coil 50A and the transmitting coil 50B) can be increased.

When voltage E is applied to transmitter coil 50B,
The current I ₂ flowing through the receiving coil 50A is I ₂ = E × jwM / ((R ₁ + jwL ₁ ) (R ₂ + jwL ₂ ) + (wM) ² )
L ₁ : Inductance of the transmission coil 50B
R ₁ : Resistance of transmitting coil 50B (sum of DC resistance and AC resistance)
L ₂ : Inductance of the receiving coil 50A
R ₂ : Resistance of receiving coil 50A (sum of DC resistance and AC resistance)
w: Angular frequency of current flowing in coil 50B
M: Mutual inductance of L ₁ and L ₂

The electromotive force E ₂ of the receiving coil 50A is E ₂ = −jwM
Therefore, the transmission power W is W = E ₂ I ₂ = (wM) ² / ((R ₁ + jwL ₁ ) (R ₂ + jwL ₂ ) + (wM) ² )
Since Q ₁ = wL ₁ / R ₁ Q ₂ = wL ₂ / R ₂ , the denominator component is (R ₁ + jwL ₁ ) (R ₂ + jwL ₂ )
= (1 / wQ ₁ L ₂ + jL ₁ / wL ₂ ) (1 / wQ ₂ L ₁ + jL ₂ / wL ₁ )
It is represented by

That is, the transmitted power W can be increased by increasing the Q values (Q ₁ , Q ₂ ) in the above formula.

  The above-described embodiment is merely an example, and can also be applied to a signal or power transmission coil using an antenna coil, electromagnetic induction or magnetic resonance, and enables efficient signal and power transmission.

  In the first embodiment, the magnetic layer 3 (13, 23) is made of an alloy containing a predetermined amount of Fe metal. In addition to this, the present inventor has found that even when the magnetic layer is made of Fe alone, the attractive force can be increased as compared with the case where the magnetic layer is not provided on the electromagnet wire.

  FIG. 7 is a cross-sectional view schematically showing a configuration of an electromagnet wire according to the second embodiment of the present invention. The configuration of the electromagnet wire according to the present embodiment is basically the same as that of the electromagnet wire according to the first embodiment, and therefore different parts will be described below.

  The electromagnet wire 161 includes a conductor 162 that is a core of the wire, a magnetic layer 163 that covers the outside of the conductor 162, a metal layer 164 that covers the outer periphery of the magnetic layer 163, and a further outer periphery of the metal layer 164. And an insulating layer 165 covering the surface. That is, the magnetic layer 163 is provided between the conductor 162 and the metal layer 164. In the present embodiment, the wire diameter of the electromagnet wire 161 is, for example, φ0.5.

  The magnetic layer 163 is formed of a film made of Fe (one element). The thickness of the magnetic layer is greater than 0 μm and not greater than 3.0 μm, and preferably not less than 1.5 μm and not greater than 3.0 μm. The metal layer 164 is formed to a thickness of the order of several μm and is made of, for example, Ni.

  FIG. 17A and FIG. 17B are cross-sectional views of a coil using the inductor wire. As shown in FIG. 17A, the air-core coil 170a in this embodiment is formed by winding an inductor wire 161 on which a magnetic layer (thickness 3 μm) made of Fe is formed into a cylindrical shape, and nothing is contained in the cylinder. It is not included. This air-core coil 170a has a diameter of 25 mm and a winding number of 150 turns. FIG. 17B shows a coil 170b in which a core 172 of a ferrite core material 171 having a substantially U-shaped cross section is disposed in the cylinder of the air core coil 170.

  18A and 18B are diagrams showing the relationship between the coil frequency and the Q value change rate shown in FIGS. 17A and 17B, respectively. From the graph of FIG. 18A, it was found that in the case of the air-core coil 170a, the Q value change rate increases as the frequency increases at a frequency of about 2 kHz to about 500 kHz. It was also found that the Q value change rate increased by about 40% at a frequency of 100 kHz, and the Q value change rate increased by about 60% at a frequency of 500 kHz.

  Further, from the graph of FIG. 18B, it was found that in the case of the coil 170b using the ferrite core, the Q value change rate increases as the frequency increases at a frequency of about 2 kHz to about 500 kHz. Further, it was found that the Q value change rate increased by about 80% at a frequency of 50 kHz, the Q value change rate increased by about 97% at a frequency of 100 kHz, and the Q value change rate increased by about 120% at a frequency of 500 kHz. Furthermore, in the frequency range of about 5 kHz or more and about 500 kHz or less, it was found that the Q value of the coil 170b using the ferrite core showed a value twice or more compared to the Q value of the air-core coil at any frequency. .

  According to the inductor wire according to the present embodiment, the magnetic layer 163 is formed of a film made of Fe, so that the Q value of the air-core coil 170a can be increased as compared with the case where the magnetic layer 163 is not provided. it can. In the case of the coil 170b using a ferrite core, a high Q value that is twice or more compared with the Q value of the air-core coil 170a can be realized in the frequency band.

  In the present embodiment, the magnetic layer 163 is made of Fe, but is not limited thereto, and may be substantially made of Fe. The same effects as described above can also be achieved by this configuration.

  Further, in the present embodiment, a single Fe element, an alloy mainly composed of Fe, or an Fe—Ni alloy is used for forming the magnetic layer, but the present invention is not limited to this, and any magnetic material can be formed. Any material may be used.

1, 11, 21, 161 Inductor wire 2, 12, 22, 162 Conductor 3, 13, 23, 163 Magnetic layer 4, 14, 24 Insulating layer 30A, 30B, 30C, 170a Air-core coil 40A, 40B, 40C Measured value 50 Air-core coil 50A Reception coil 50B Transmission coil 164 Metal layer 170b Coil using ferrite core

Claims (14)

An inductor wire used for an inductor coil,
Having a conductor and a magnetic layer provided on a surface layer of the conductor;
An inductor wire, wherein the magnetic layer has a thickness greater than 0 and not greater than 3.0 μm.   2. When the operating frequency band is 0.01 to 1000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 100 to 500, and the thickness of the magnetic layer is greater than 0. It is 0 micrometer or less, The wire for inductors of Claim 1 characterized by the above-mentioned.   When the operating frequency band is 0.01 to 5000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 100 to 500, and the thickness of the magnetic layer is larger than 0. It is 0 micrometer or less, The wire for inductors of Claim 2 characterized by the above-mentioned.   When the operating frequency band is 0.01 to 1000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 500 to 2000, and the thickness of the magnetic layer is larger than 0. It is 5 micrometers or less, The wire for inductors of Claim 1 characterized by the above-mentioned.   When the operating frequency band is 0.01 to 1000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 500 to 2000, and the thickness of the magnetic layer is larger than 0. The inductor wire according to claim 4, wherein the inductor wire is 0 μm or less.   When the used frequency band is 0.01 to 5000 kHz or less, the value obtained by expressing the initial permeability of the magnetic layer in terms of relative permeability is 500 to 2000, and the thickness of the magnetic layer is 0.5 to 1 The inductor wire according to claim 1, which is 0.5 μm.   The inductor magnetic wire according to any one of claims 2 to 6, wherein the magnetic layer is an alloy of two or more elements containing 10% or more by weight of Fe.   The inductor wire according to claim 7, wherein the magnetic layer is an Fe-50Ni alloy.   The inductor wire according to claim 7, wherein the magnetic layer is an Fe-80Ni alloy.   The inductor wire according to claim 1, wherein the magnetic layer is substantially made of Fe.   11. The inductor wire according to claim 10, wherein a thickness of the magnetic layer is greater than 0 μm and equal to or less than 3.0 μm.   The inductor wire according to claim 11, wherein the magnetic layer has a thickness of 1.5 μm to 3.0 μm.   13. The inductor wire according to claim 1, wherein the magnetic layer is provided between the conductor and the insulating layer.   An inductor using the inductor wire according to any one of claims 1 to 13.

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